Mechanical interlocks for plural electrical apparatus



y 3, 1957 E. w. SEEGER 2,800,034

MECHANICAL INTERLOCKS FOR PLURAL ELECTRICAL APPARATUS Filed March 4,195:5

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MECHANICAL INTERLOCKS FOR PLURAL ELECTRICAL APPARATUS Edwin W. Seeger,Wauwatosa, Wis., assignor to Cutler- Hammer, Inc., Milwaukee, Wis., acorporation of Delaware Application March 4, 1953, Serial No. 340,220

9 Claims. (Cl. 74-483) This invention relates to mechanical interlocksfor plural electrical apparatus.

A primary object of the invention is to provide a reliable mechanicalinterlock for plural electrical apparatus which is simple to install andinexpensive to manufacture.

Other objects are to provide such an interlock which may be readilyadapted for use with plural electrical apparatus of various sizes andtypes, and which imposes few limitations with respect to the relativeplacement and positioning of the apparatus interlocked as compared withthe limitations of previously known interlocks.

Other objects and advantages of the invention will hereinafter appear.

The objects are attained by the provision of a hollow, sealed memberhaving a flexible portion which is filled with a substantiallyincompressible liquid to a volume which is some predetermined amountless than the maximum volume of said hollow member when in its normalconfiguration. The material of which the hollow member is formed isselected so that the walls of the finished interlock may be easilydepressed or deformed but may not be easily distended or ballooned toincrease the volume of the hollow member beyond its maximum volumetriccapacity when in its normal configuration. Such an interlock, when usedwith plural electrical apparatus each of which is provided with asuitable interlock mechanism, provides a very flexible and reliableinterlock system. The interlock is positioned relative to such interlockmechanisms so that upon being actuated the mechanism depresses ordeforms the interlock sufiiciently to decrease the total volumetriccapacity of the interlock, without distention thereof, to substantiallythe volume of the liquid contained therein.

Thus if any one of the interlock mechanisms is actuated to deform theinterlock, the other interlock mechanisms are prevented from beingactuated because further depression of the interlock would requiredistention or ballooning of the hollow interlock member.

While such member is preferably formed of a relatively inelasticmaterial, such materials as rubber and elastomers perform satisfactorilysince hollow bodies of such materials may be more readily deformed thandistended.

The accompanying drawing illustrates one embodiment of the inventionwhich will now be described. It is to be understood, however, that theembodiment selected for illustration is merely representative of theembodiments contemplated and which lie within the spirit and scope ofthe appended claims.

In the drawings, Figure 1 is a partially schematic, isometric view of aninterlock system embodying the invention;

Figures 2 and 3 are enlarged, fragmentary, isometric views illustratingalternative means for mounting an interlock embodying the invention; and

Fig. 4 is a diagrammatic illustration, partly in elevation and partly invertical section, of a modified form of the invention.

United States Patent Referring to the drawing, the enumeral 10designates a panel and 12 is a sub-panel mounted in a fixed relationshipthereto. A relay 14 and a contactor 16 are mounted on one side, and acontactor 18 is mounted on the other side of panel 10. A solenoid 20 ismounted on the sub-panel 12. Relay 14, contactors 16 and 18, andsolenoid 20 are provided with interlock mechanisms 14, 16 18 and 20*,respectively.

An interlock 22 comprising a flexible, hollow, sealed, tubular member 24containing a substantially in'conipress ible body of liquid fill 26extends along one surface of panel 10, through opening 28 in panel 10,along the other side of panel 10 and then to and along the surface ofsubpanel 12. The interlock is disposed in such manner that it iscooperatively engageable by the engaging face of each of the mechanisms14*, 16 18 and 20. It is secured to panel 10 and sub-panel 12 by anyappropriate means such, for example, as by clamps 30, one of which isshown in Fig. 2, or by a channel 32, Fig. 3, attached to the panel, andto which the interlock is secured in any suitable manner, as by adhesivecement or the like as indicated at 34.

Hollow member 24 will accommodate a given maximum volume of liquid 26when in its normal configuration (i. e., that configuration it wouldassume without being distended or ballooned in any dimension). Theactual volume of liquid 26 which is contained in member 24 is apredetermined amount less than such maximum volume. Air pressureexternal to member 24 will collapse the latter so that liquid 26 fillsthe same. If desired air or other compressible fluid may be permitted tooccupy that portion of the hollow member not occupied by liquid 26.

The relay 14, contactors 16 and 18 and solenoid 20 are so positionedrelatively to interlock 22, and the strokes, lever arms and the areas ofthe engaging faces of the respective mechanism 14 16 18 and 20 are soproportioned that, in the embodiment illustrated, any one, but only one,of the mechanisms may be actuated at one time. For certain applications,less liquid fill may be used to permit more than one mechanism to beactuated at one time.

If preferred, the strokes, engaging forces and areas of the engagingfaces of the several actuating members may be so proportioned and thevolume of the liquid fill may be so proportioned relative to thevolumetric capacity of the hollow member 24 that actuation of certaininterlock mechanisms is effective to prevent actuation of certain otherinterlock mechanisms. One example is illustrated diagrammatically inFig. 4, wherein a hollow member 38 containing a predetermined quantityof liquid 40 is adapted to be depressed by actuating mechanisms 42, 44,46 and 48. The reduction in the volumetric capacity of member 38 whichis effected by actuation of mechanism 42 is equal to such reductioncaused by actuation of mechanisms 44 or 46, but is equal to onlyone-third of such reduction caused by actuation of member 48. Thusactuation of mechanism 48 precludes actuation of mechanisms 42, 44 and46 or any of them. Actuation of one of the smaller mechanisms would notprevent actuation of one or both the other smaller mechanisms, but wouldprevent actuation of mechanism 48.

The provision of other numbers of actuating mechanisms and/or actuatingmembers of other relative sizes makes possible interlocking systemswhich would be difficult and costly to duplicate by mechanicalinterlocks heretofore known.

The interlock 22 may be pre-shaped to suit a given arrangement of theapparatus to be interlocked. However, the primary advantage of theinvention is that the flexibility of the interlock permits theadaptation of standard forms of the interlock to various arrangements ofappara- 3 tus. Thus as illustrated in Fig. 1, a length of straighttubing may be bent to lie in various planes, to extend to the oppositeside of the panel, or even to extend to other panels. The apparatusinterlocked may be placed and oriented according to other requirementsthan the necessity of interlocking.

Any kinks or the like which are formed in the interlocks in assemblingthe system would change the volumetric capacity of the interlock, andobviously would cause difficulty, such difliculties may be easilyavoided by the use of preformed sections, such as metal elbows or thelike, to replace portions of the flexible member, or by filling andsealing the interlock after it is installed. Or, alternatively, suchdifliculties, or difficulties caused by filling the hollow member withan improper volume of liquid, may be overcome by employing clampingmeans for adjusting the volumetric capacity of the member.

I claim;

1. In a mechanical interlock for plural electrical apparatus, incombination, a hollow sealed member having a flexible portion, saidmember containing a volume of substantially incompressible liquid, saidvolume being some predetermined amount less than the volumetric capacityof said hollow sealed member in its normal configuration, a plurality,exceeding two in number, of electrical devices each having an operatingmechanism including an element individual thereto, each said elementhaving an unoperated position in which said element is disengaged fromsaid flexible portion and an operated position in which said elementdepresses said flexible portion to decrease said volumetric capacity ofsaid hollow sealed member, and means for actuating one of said elementsinto its operated position wherein said liquid at said decreasedcapacity of said hollow sealed member locks at least one of said otherelements in unoperated position.

2. An interlocking apparatus of the character set forth in claim 1, inwhich said hollow sealed member is of tubular form between therespective closed ends thereof.

3. In a mechanical interlock for plural electrical apparatus, incombination, a plurality, exceeding two in number, of electrical deviceseach having an interlock element operatively associated therewith, asealed flexible tubular member normally engaged with said interlockelements, said tubular member containing a body of-substantiallyincompressible liquid occupying a volume which is some predeterminedamount less than the total normal configuration volumetric capacity ofsaid tubular member, means for operating one of said interlock elementsto depress a portion of said flexible tubular member to decrease itsvolumetric capacity, whereby said liquid is confined in said decreasedcapacity to prevent operation of at least one of said other elements.

4. In a mechanical interlock for plural electrical apparatus, incombination, a plurality, exceeding two in number, of electricallyoperated devices each having an interlock element operated jointlytherewith, a sealed flexible tubular member cooperatively arranged withrespect to each of said interlock elements, said sealed flexible membercontaining a body of substantially incompressible liquid occupying avolume which is a preselected amount less than the normal configurationvolumetric capacity of said member, said sealed flexible tubular memberbeing deformable without distention thereof, and means for operating oneof said elements to depress a portion of said flexible tubular member todecrease its volumetric capacity, whereby said liquid is confined insaid decreased capacity to prevent operation of one or more of the otherof said elements.

5. In a mechanical interlock for plural electrical apparatus, incombination, a plurality, exceeding two in number, of electricallyoperated devices each having an interlock element operated jointlytherewith, a sealed flexible tubular member cooperatively arranged withrespect to each of said interlock elements, said sealed flexible tubularmember containing a body of substantially incompressible liquidoccupying a volume which is at least one times some predetermined amountless than the normal configuration capacity of said member, said sealedflexible member being deformable without distention thereof, and meansfor effecting operation of one or more of said elements to depress aportion or portions of said flexible tubular member to correspondinglydecrease its volumetric capacity, whereby said liquid is confined insaid decreased capacity to thereby prevent operation of one or more ofthe other of said elements.

6. In a mechanical interlock for plural electrical apparatus, incombination, a plurality of electrical devices, exceeding two in number,each having an interlock element operated jointly therewith, a sealedhollow flexible member positioned for engagement by one or more of saidinterlock elements either individually or jointly, and a body of liquiddisposed within said hollow member, said interlock elements each beingadapted upon a given operation thereof to effect depression of saidhollow member to reduce the volumetric capacity of the latter, withoutdistention thereof, some predetermined amount, said body of liquidhaving a volume substantially equal to the volumetric capacity of saidhollow member, when in its normal configuration, less at least one timessaid predetermined amount, and means for actuating at least one of saidelements into its operated position wherein said liquid at saiddecreased capacity of said sealed hollow flexible member effects lockingof at least one of said other elements in unoperated position.

7. An interlocking apparatus like that defined in claim 6, wherein saidsealed hollow flexible member is of tubular form between the respectiveclosed ends thereof.

8. In a mechanical interlock for plural electrical apparatus, incombination, a plurality, exceeding two in number, of electrical deviceseach having an interlock element to be actuated thereby, a sealed hollowmember having a flexible portion positioned for engagement by one ormore of said interlock elements either individually or jointly, a bodyof liquid disposed within said hollow member, each interlock elementacting automatically, upon energization of its associated electricaldevice selectively, to reduce the volumetric capacity of said hollowmember, Without distention thereof, at least one times somepredetermined amount, and said body of liquid having a volumesubstantially equal to the volumetric capacity of said hollow memberwhen in its normal configuration less at least two times saidpredetermined amount.

9. In a mechanical interlock for plural electrical apparatus, a hollowsealed member comprising a flexible portion and a single chambercontaining a volume of substantially incompressible liquid, said volumebeing some predetermined amount less than the volumetric capacity ofsaid hollow sealed member in its normal configuration, said hollowsealed member being deformable without distention thereof, and aplurality of electrical devices each having an operating mechanismincluding an element individual thereto, each said element having anunoperated position in which said element is disengaged from saidflexible portion and an operated position in which said elementdepresses said flexible portion to decrease said volumetric capacity ofsaid hollow sealed member, means for actuating a desired one of saidelements into its operated position, the area of at least one of saidelements being a multiple of the area of other of said elements so thatwhen said one element is actuated into its operated position said liquidat the decreased capacity of said hollow sealed member locks said otherelements in unoperated position, and when only one of said otherelements is actuated into its operated position said liquid at thedecreased capacity of said hollow sealed member locks only said multiplearea element in unoperated position.

(References on following page) References Cited in the file of thispatent UNITED STATES PATENTS Sears July 5, 1898 Dunford Dec. 15, 1931Uhde June 22, 1937 Stubbins Feb. 8, 1938 Sharp Apr. 4, 1939 6 RubissowJan. Reckham Feb. Grossenbach Jan.

FOREIGN PATENTS Great Britain Aug. Germany Nov.

